1. Field of the Invention
The present invention relates to a communication system, management apparatus and method for restricting functions in a communication system and, for example, to the assignment of functional restrictions to electronic devices used by participants of a conference using a conference system.
2. Related Background Art
A conventional conference has a disadvantage that materials to be released are distributed to all participants on a paper basis, which leads to waste of resources. Furthermore, it also involves a disadvantage that when the number of materials is not enough for all participants, the necessary materials need to be copied in haste, which may interrupt the progress of the conference.
On the other hand, it is becoming a general practice in recent years that participants bring a PC (personal computer), PDA (Personal Digital Assistants) into a conference room and materials to be released are projected by a projector and presented. Moreover, the above disadvantages are covered by distributing document data to participants other than the presenter through a network, not on a paper basis.
However, in the case of a conference with many participants if all participants use a network, this leads to another disadvantage that wiring becomes complicated. To handle this additional disadvantage, a conference system using a wireless communication such as Bluetooth is now under consideration.
Since the Bluetooth system performs ad-hoc multi-point connections, it can construct a pico-net with a maximum of 8 devices connected and a communication range of 10 m and communicate and provide an asynchronous communication with downlink 721 Kbps and uplink 57.6 Kbps. It also supports speech communications, has the ability to transfer speech and data through a single channel, etc., and in this way it is expected to be used for applications in a variety of platforms.
The conference system using the wireless communication such as Bluetooth described above may eliminate complicated wiring, but it involves another disadvantage in an aspect of security due to illegal access and data tampering, etc., from the outside through wireless connections.
Moreover, another disadvantage is that once a user is authenticated, the Bluetooth authentication level cannot prevent the user from copying a document, printing it or overwriting data.
In order to overcome the above-described disadvantage, there is a proposal about a method for improving utility and security levels by using two types of PIN codes; private PIN codes and temporary PIN codes for different devices depending on their modes of use (e.g., see Document 1 (U.S. Patent Publication No. 2001036273). There is also another proposal about a method of specifying authorization in a conference for each terminal and restricting their functions (e.g., see Document 2 (EP A2 1249097)).
Furthermore, a standard or work intended to enhance security using a Port Based Network Access Control technology is underway to cope with the problems with illegal access, data tampering or access control (e.g., see Document 3 (IEEE802.1x (Institute of Electrical and Electronic Engineers 802.1x)).
The invention described in Document 2 selects, when giving authorization to devices of participants, a tab for specifying the authorization with which each participant participates in the conference from an application on a conference system and sets the authorization according to the selected tab.
However, the problem with such a system is that it not only takes time and trouble for participants but also allows the participants to change the setting of the authorization arbitrarily or manipulate data by changing the authorization deliberately.
On the other hand, the invention described in Document 3 installs a RADIUS (Remote Authentication Dial-In User Service) server as a terminal authentication server and adopts a method for performing authentication using an electronic certificate or password, etc., with the authentication server before each terminal accesses a conference system.
However, such a configuration allows only conference participants who have terminals supporting an IEEE802.1x compatible program to participate in the conference and the problem is that participants having terminals manufactured before IEEE802.1x was considered or participants having a device such as a PDA (Personal Digital Assistance) which is often provided with Bluetooth but not supporting IEEE802.1x cannot participate in the conference.